Automatic non-interfering repeater for fire-alarm circuits



No. 749,387. PATENTED JAN. 12, 1904. I I W. H. KIRNAN.

AUTOMATIC NON-INTERFERING REPEATER FOR FIRE ALARM CIRCUITS.

APPLIOATIONIILED 0OT.4, 1902.

N0 MODEL. 5 SHEETS-SHEET 1.

Witnesses Inventor I A I M Attorneys THE scams PETERS co FHOTOLITNQ.WASHINGTON, n. c.

No. 749,387. PATENTED JAN. 12, 1904. W. H. KIRNAN. AUTOMATICNON-INTERPERING RBPEATER FOR FIRE ALARM CIRCUITS.

APPLICATION FILED OOT. Q, 1902.

5 SHEETS-SHEET 2.

no MODEL.

Inventor Attorneys PATBNTED JAN. 12, 1904.

W. H. KIRNAN. AUTOMATIC NON-INTERFERING REPEATER FOR FIRE ALARMCIRCUITS.

APPLICATION FILED OCT. 4, 1902 5 SHEETS-SHEET 3.

R0 MODEL.

N 0 W A w w w j w INSULATION Inventor I Witnesses Attorneys,No.749,38'7. PATENTED JAN. 12.1904.

- W. H. KIRNAN.

AUTOMATIC NON-INTERFERING REPEATER FOR FIRE ALARM CIRCUITS.

APPLICATION FILED 001'. 4, 1902.

N0 MODEL. 5 SHEETS-SHEET 4.

' Witnesses: Ihvpntor wyfim MW m 5 Attor ys UNITED STATESPatentedJanuary 12, 1904.

PATENJLLQEELQE.

WILLIAM H. KIRNAN, OF BAYONNE, NEW JERSEY, ASSIGNOR TO THE GAMEWELL FIREALARM TELEGRAPH COMPANY, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

. AUTOMATIC NON- INTERFERING REPEATER FOR FIRE-ALARM CIRCUITS.

SPECIFICATION forming part of Letters Patent No. 749,387, dated January12, 1904.

. Application filed October 4, 1902. Serial No. 125,947. (No model.)

To all whom it may concern.-

Be it known that I, VVILLrAM H. KIRNAN, a

, citizen of the United States, residing at Bayonne, in the county ofHudson and State of New Jersey, have invented a certain new and usefulImprovement in Automatic Non-Intel fering Repeaters for Fire-AlarmCircuits, of

which the following is a description.

one or more street-circuits will not prevent the effective operation ofthe repeater from other street-circuits.

At the present time in the installation of firealarm apparatus theseveral street-circuits lead to a so-called repeate1-,bymeans of whichthe signals are relayed or distributed over one or more joker-circuitsleading to the several engine-houses and also ordinarily to the mainwhistle or bell. The employment of. non-interfering street-boxesprevents confusion on any particular street-circuit by the concurrentoperation of more than one street-box in that circuit even if a numberof street-boxes are pulled simultaneously and results in the successivetransmission of signals to the repeater from the several boxes whichhave thus been operated. \Vith repeaters as so far developed,

however, no adequate provision has been made for the prevention ofconfusion in the trans, misslon of s gnals over the JOkGT-CllCllllJSwhen signals on a plurality of street-circuits interfere. My principalobject, therefore, is to so improve the construction and operation of repeaters that they shall possess all the attributes of the mosthighly-developed street-boxes namely, to prevent interference of signalstransmitted concurrently from a plurality of I street-circuits even whenthe interference is such that a signal from two or more streetboxes maybe received at the repeater at the same instant of time.

Ordinarily the street-circuits are normally closed on the repeater andthe transmission of signals is effected by successively breaking thestreet-circuits in the desired sequence. Since the non-interferencemechanism, which I prefer to employ, is operated concurrently with thebreaking of any one or more of the street-circuits, it will be obviousthat a permanent disabling of a street-circuit, as by a ground or breaktherein, would result in confusion in the operation of the othercircuits. A secondary object of the invention, therefore, is to provideimprovements by reason of which the disabling of any street-circuit willnot affeet the proper and non-interfering operation of the repeater fromthe other street-circuits.

In carrying the invention into efi'ect I employ a repeater having,preferably, the ordinary joker transmitting apparatus and operate themechanism thereof by a main operating-magnet, which in the preferredinstance is inanormally open local circuit. Each streetcireuit leads toa street-magnet and is preferably normally closed. The release of thearmature of any street-magnet by the breaking of one of thestreet-circuits operates a circuitbreaker, which closes the localcircuit on the main operating-magnet and results in the operation of thejoker-transmitter, which therefore repeats the signal over theengine-house circuit or circuits; A number of non-interference magnetsare employed corresponding with the street-magnets, and thesenon-interference magnets are preferably also located in a normally openlocal circuit, which, however, is mechanically closed at thecommencement of the operation of the repeating apparatus. Thecircuit-closing devices for closing the circuit to themainoperating-magnet when in their normal position close a correspondingseries of breaks in the non-interference circuit, and thesecircuit-closing devices cooperatewith the armatures of thenon-interference magnets, whereby when such armatures are retracted thecircuit-closing devices corresponding to the same will be locked againstoperation, while, on the other hand, when any one of the circuit-closingdevices is operated to close the circuit to the main operating-magnetthe corresponding armature of the noninterference magnet will be heldfrom moving to a retracted position. I make use of mechanical restoringdevices for restoring the armatures of the street-magnets andnon-interferencemagnets atthe end of the operation of the repeatingmechanism and for releasing such armatures at the commencement of thatoperation. With an apparatus having these characteristics, the detailsof which will be more fully hereinafter described, interfer ence in theoperation of the repeater is absolutely prevented, while at the sametime successive operation of relatively concurrent signals received overaplurality of street-circuits is automatically eifected.

In order that the invention may be better understood, attention isdirected to the accompanying drawings, forming part of thisspecification, and in which Figure 1 is a plan view of a well-known formof repeater with my present improvements applied thereto; Fig. 2, a sideelevation; Fig. 3, an end view; Fig. 4, a section on the. line 4 4 ofFig. 1; Figs.'5 and 6, enlarged detail views illustrating one of theswitches and the parts immediately cooperating therewith in the normaland retracted positions of the armature of the correspondingstreet-magnet; Fig. 7, detail views illustrating one of the pins on theseveral street-magnet armature-levers and the hook with which itcooperates and showing the different positions of these parts in theoperation of the device, and Fig. 8 a diagram illustrating the severalcircuits.

In all of the above views corresponding parts are represented by thesame numerals of reference.

The general construction of repeaters of the type shown in the drawingsis so well known that a detailed description and illustrationof the sameare not necessary. The repeater comprises an insulated cylinder 1,having contact-plates thereon which normally engage with contact-springs2 in circuits 3 3, leading to the several engine-houses. All of thesecircuits will therefore be simultaneously broken when the cylinder 1makes a complete rotation. The cylinder 1 is driven by a suitablegearing from a weight 4. Carried on the shaft of the cylinder 1 is anarm 5, provided on its lower end with a pin, which normally engages astud 6 on an operating-lever 7. When this operating-lever iselevated,the arm 5 is released and rotates until the pin on its endengages a stud 8 on the lever 7, again closing the circuits 3. Thereturn of the lever 7 to its normal position results in the rengagementof the pin on the lower end of the arm 5 with the stud 6, so that theparts once again occupy their normal positions. The lever 7 is carriedon a shaft 9, to which an armature 10 is connected. This armature isattracted by the main operating-magnet 11. Obviously when the circuit tothe magnet 11 is closed and broken the cylinder 1 of the repeatingmechanism will make a complete rotation. The shaft of the cylinder 1 isprovided with the usual cam 12 for operating a trip-lever 13, the latterbeing frictionally connected with a winding-drum 14, operated by aweight 15. When the trip-lever 13 is moved upwardly by the cam 12, ittrips a drum 16, operated by a weight 17, and by means of an escapement(not shown) permits the said drum to make a half-rotation; Thetrip-lever 13 is slowly returned toward its normal position by theoperation of the weight 15, and when its normal position is reached theescapement mechanism for the drum 16 again operates and allows thelatter to return to its normal position. The drum 16 is connected by asuitable gearing with the shaft 18, which effects the release andrestoration of the several armatures, to be presently described. Theconstruction and operation of the repeater which I have so far brieflyoutlined are well known to those skilled in the art. Repeaters of thistype are described and illustrated in patents to Rogersand Crane, No.223,248, of January 6, 1880; to Skelton, No. 596,250, of December 28,1897, and to Kirnan, No. 650,358, of May 22, 1900, and difier from myrepeater as so far described only in the single respect that with theprevious devices trip-lever 7 has been operated by a rock-shaft, (see,for example, the rock-shaft 10 and link 11 of the Kirnan patent lastreferred to,) whereas with my repeater the trip-lever is operated by themagnet 11.

Mounted on the base of the apparatus are street-magnets 19, one for eachstreet-circuit, the latter being normally closed, as shown in Fig. 8.The armatures 20 of the street-magnets are retracted by an adjustablespring 21 when any one of the street-magnets is deenergized, and theirrearward movement is limited by a screw-stop 22. At the upper end ofeach armature-lever is a screw 23, which cooperates with one arm of abell-crank 24, mounted on an insulating-block 25, carried on a rod 26,extending across the street-magnets. The other arm of each bell-crank isprovided with a finger 27, which cooperates with a notch in thearmature-lever of the corresponding non-interference magnet, as will bepresently explained. Pivoted on the other side of each of theinsulating-blocks 25 is a switch 28, normally engaging a contact 29, butadapted to engage a contact when the switch is moved downwardly to theposition shown in Fig. 6 and in dotted lines, Fig. 4. This switch isprovided with a slotted head, with which an insulated stud 31 on thecorresponding bellcrank 24 engages. The restoring-shaft 18 carries theusual arm 32, which operates a lever 33 on a rock-shaft 34. Secured tothis rock-shaft are a number of arms 35, corresponding to thestreet-magnets and provided with adjusting-screws 36, Fig. 4, whichengage the armature-levers of said magnets to makes the second half ofits rotation.

circuits become disabled.

restore the same when the restoring shaft Aswill be presently explained,this mechanical restoration of the armatures of the street-magnets isnecessary in case one or more of the street- A number of non-interfmagnet. The armature-levers 38 of the nonf the parts to hold thearmatures of the non- I armature-lever 38 is an arm. on arockshaft 41,arranged in the normal pos tion of interference magnets in contact withor closely adjacent to the poles thereof. secured to therock-shaft 41and is connected 2 5 provided w'ithan inclined or cam portion 47,

An arm 42 is by a link, as shown, with an arm 43, loosely pivotedon therock-shaft 34 and operated by with which an insulating-pin48 on therockshaft41'engages. The armature-lever 38 of.

, each non-interference magnet is provided with i a notch 49 in linewith the finger 27 of the corresponding bell-crank 24. The parts are soproportioned that when any armature-lever of a non-interference magnet1s moved to a retractedposition (see dotted lines, Fig. 3),

35. the particular bell crank in question fronr movement by its spring50. I When, however,

thefinger 27 of thecorresponding bell-crank will be projected throughthe notch to lock any oneof thebell-cranks is moved, (see Fig. 6 anddotted lines, Fig. 4,) the finger 27 therei the corresponding noninterference magnet and prevent thearmature thereof from being "movedoutof the field of theparticular nonw f interference magnet in questionwhen the cirof will'act as a stop for thearmature-lever of cuit theretois closed.

The armature-lever of eaclrstreet magnet is provided nearits upper endwith a pin 51,

of the arm 53 and holds it in its normal posi,

hangs the shank thereof, so thatthe pin 51 i on the correspondingarmature-lever will which cooperates with a hook 52, carried at the endof an arm 53 ,pivoted to a stationary bracket 54. A leaf-spring 55engages the top tion. As shown in Fig. 7,the hook 52 overwhenthearmaturelever is retracted pass beneath the hook (see 5, Fig. 7 toslightlyelevate the pivoted arm 53, while upon the restoration of saidarmature-lever thepin rides 6: up on the. top of the hook (see c, Fig.7) t0,

depress said arm}, The parts are so adjusted that therestoring-shaft 18moves the armature-levers only to a suflicient extent to en-.

age the several pins 51 with the hooks 52 see (Z, Fig. 7) and does notmove the armature-levers to their complete attracted posii erencemagnets 37 corresponding w th the street-magnets, are employed,one bemglocated over each street- A pair of 3 to the several engine-houses.

tion, (see a, Fig. 7,) in which the pins are brought completely to therear of said hooks. This latter movement of the armature-leversiseffected by the attraction of the street-magnets themselves, and inthe event of a break in the street-circuit the correspondingarmature-lever will remain hooked in an almost completely retractedposition, as will be obvious. In this position-namely, Withthe pin 51 inengagement with the hook52, as shown at (Z, Fig. 7 the switch 28 will bemaintained in engagement with the upper contact-plate 29 therefor, sothat notwithstanding the disabling of any street-circuit thestreet-magnet will not aifect the non-interference circuit.

The preferable electrical connections are shown. in Fig. 8, in which forthe. purpose of diagrammatic illustration the switches 28 andbell-cranks 24 are shown as a singleelement. The street-magnets 19 arein closed street-circuits 56, each containing one or more streetboxes57. The main operating-magnet 11 is in a normally open local circuit 58,including a local battery 59, which local circuit is adapted to beclosed at any one of the contacts 30 by the operation of thecorresponding switch 28. The several non-interference magnets 37 areconnected in series in a local circuit 60,

which includes the contact-swings 45 and 46 and the contacts29, withwhich the switches 28 are normally in circuit. The local circuit for thenon-interference magnets isnormal'ly broken at the springs 45 and 46..\V hen,

however, the repeating mechanism starts to operate, the circuit to thenon-interference magnets will be closed, and the subsequent operation ofthe nonsinterference mechanism will therefore be the same as if anormally closed local circuit were used. By adopting this expedient 1amtherefore enabled to operate the non-interference mechanism on apractically closed local circuit without, however, draining the localbattery when the device is not in operation.

Assuming a signal to be sent in over one of the street-circuits andwithoutany interference from other street-circuits, the operation of theapparatus is as follows: When one of the street-circuits is broken, itsarmature-lever is retracted by the spring 21 to the position shown indotted lines, Fig. 4. This movement permits the spring 50 to operate thecorresponding bell-crank 24, which moves the switch 28 into engagementwith the contact-plate 30.

The local circuit 58 is therefore closed on the main operating-magnet 11through the several levers 28 and contacts 29, attracting the armature,10, elevating the lever 7, releasing the arm 5, and permitting thecircuit-breaking cylinder 1 to make almost a complete rotation, breakingand again reestablishing the circuits When the street-circuit is againclosed, the armature thereof will be attracted, moving the bellcrank 24to its normal position and again enits normal position.

operates the cam 12 to elevate the trip-lever 13 to thereby trip theshaft 18 and permit it to make a half-rotation. In this movement of therestoring-shaft 18 the cam 44 will be retracted from the arm 43 torelease the rockshaft 41. As soon as this rock-shaft is released. all ofthe armature-levers of the noninterference magnets except thatcorresponding to the street-magnet in operation will be retracted by thesprings 39 and moved to the position shown in dotted lines, Fig. 3, toengage the notches 49 over the fingers 27 and prevent the operation ofthe corresponding switches 28. In this position the armature-levers ofthe non-interference magnets are out of the influence of those magnets,so that a closing of the non-interference circuit will not affect theretracted armatures. It will be obvious that the armature-lever of thenon-interference magnet corresponding to the street-magnet in operationwill not be retracted like the armature-levers of the othernon-interference magnets, since the finger 27 of the street-magnet inoperation will occupy the position shown in dotted lines, Fig. 4, toblock the armaturelever of the non-interference magnet and prevent itfrom being retracted. The movement of the rock-shaft 41 referred toengages the insulating-finger 48 with the spring 46 to close thenon-interference circuit at this point; but

the non-interference circuit will be broken at ture-lever of thenon-interference magnet in question will be still held in an attractedposition, since the non-interference circuit will be closed by thereengagement of the switch 28 with thecontact-plate 29.

From what has been said it will be seen with respect to thearmature-lever of any one of the non-interference magnets that saidarmature-lever is during the operation of its particular street-magnetmaintained in an attracted position, first mechanically and thenmagnetically2'. 6., when the street-magnet is deenergi zed to close thelocal circuit 58 the armature-lever will be mechanically held in thenon-interference magnets to magnetically attract the armature-lever inquestion. Thus the armature-lever of the non-interference magnetcorresponding to the street-magnet in operation is prevented frominterfering in any way with the operation of the switch correspondingthereto to close the circuit 58 on the main operating-magnet 11. In thecase of the other non-interference magnets, however, their armaturesbeing in the position shown in dotted lines, Fig. 3, lock thebell-cranks 24 of all the other street-magnets, so that if a signal istransmitted over any other streetcircuit except that which commenced tofirst operate it results only in the movement of the armature-leverswithout effecting a movement of the corresponding switches to actuatethe magnet 11, controlling the operation of the repeater. In this way byarranging the parts so that the operation of any one of the armatures ofthe street-magnets will be immediately followed by a retraction of thearmature-levers of the non-interference magnets for all the otherstreet-magnets to thereby lock the switches controlled by such otherstreet-magnets to prevent the latter from controlling the repeatingmechanism 1 effectively prevent interference, as will be evident, itbeing understood, of course, that the armature-lever of thenon-interference magnet for the street-magnet in operation is heldmechanically and electrically in an attracted position, so as not tointerfere with the operation of the switch 28 for the particular magnetin question, 'as explained. After the signal has been sent in thetrip-lever 13 will regain its normal position to trip the shaft 18 andallow the latter to make a half-rotation to regain its normal position.In this movement the arm 32 engages with the lever 33 and moves it inthe direction of the magnets to move the armatures almost to theircomplete attracted position or, in other words, to move the armatures tothe position where the pin 51 engages over the hook 52. (See (Z, Fig.7.) The shaft '18 completes its half movement, which will cause the arm32 to swing past the end of the lever 33, permitting it to be returnedto its original position by the action of its controlling-spring. Thismovement of the rock-shaft also causes the cam 44 to move the arms 43and 42 to swing the rockshaft 41, returning the retractedarmature-levers of the non-interference magnets to their attractedposition and holding them in that position (see Fig. 3) ready for a newoperation. This movement of the rock-shaft 41 also draws the finger 48from the spring 46 to break the non-interference circuit at that point.

My improved non-interference mechanism is so perfect in lts operatlonthat it prevents interference between signals received on (11fferentstreet-circuits, even when the first signal is received simultaneouslyon a number of circuits. This will be understood from a consideration ofthe diagram shown in Fig. 8, in

which the signal transmitted over the streetvented from disabling thetwo street-magnets in operation. Thearmature-lever for the centralstreet-magnet will, however, move to its retracted position to disablethe same. In

sending the second signal over the two outside street-circuits both themagnets Wlll ag'aln lease of the armature of the non-interferenceoperate in unison and neither will be disabled by its non-interferencemagnet. The third signal obviously is received only on the righthandstreet-circuit and results in demagnet-' izing the correspondingstreet-magnet 19, so as to break the non-interference circuit 60 betweenthe contact 29 and the switch 28 therefor. The movement downward of theswitch 28 of the right-hand street-magnet carries the finger 27 belowthe notch in the corresponding non-interference armature, as shown indotted lines, Fig. 4-, sothat the non-interference magnet does notdisable the right-hand street-magnet. The breaking of thenon-interference circuit 60, however, permits the re- 1 magnet at theleft, (see dotted lines, Fig. 3,)

so as to disable the left-hand street-magnet in just the same way as themiddle street-magnet was disabled upon the reception of the first twosignals from the rightand left hand streetmagnets. Consequently thefurther signals will be transmitted by the single street-circuit at theright, and no interference from the In this way it will" ceiving thesignal will continue to operate until its entire signal has beenreceived. Thus it becomes possible to efi'ectively operate the devicewithout interference, even when a portionof the signals are received atthe same instant by a plurality of the street-magnets.

In the event of one of the street-circuits becoming disabled, as by abreak or ground therein, it will be seen that unless sucha contingencywere provided for the release of the corresponding street-magnetarmature would send a single impulse over the circuits 3 and permit theswitch 28 thereof to remain in engagement with the contact-plate 30 tothereby keep the circuit 58 closed on the magnet 11. This wouldobviously prevent the other streetmagnets from affecting that circuit.By providing the street-magnet armatures with pins 51 cooperating withhooks 52, as explained,

this difliculty is overcome, since the operation of the restoring-shaft19 will carry the pin into engagement with the hook (see d, Fig. 7 tohold the switch of the magnet in question in engagement with the contact29, breaking the circuit 58 at the contact 30. Thus in the event of oneof the streetcircuits becoming disabled after its magnet 19 has onceoperated the controlling-magnet 11 its armature will be restored untilits pin 51 engages the corresponding hook 52, and the armature will thenremain in that-position, so as not to interfere in any way with theoperation of the magnets of the other street-circuits. As

soon as the disabled street-circuit has beenrepaired and the circuit isonce again closed its street-magnet will attract its armature and movethe pin 51 from the position shown at d, Fig. 7, to the normal retractedposition, as shown at a, Fig. 7 r

Having now described my invention, what I claim as new, and desire tosecure by Letters Patent, is as follows:

1. In a non-interference repeater for firealarm circuits, thecombination with repeating mechanism and a plurality of street-magnetscontrolling the same, of a normally open circuit embracingnon-interference magnets corresponding with the street-magnets, meanscontrolled by the non-interference magnets for preventing the operationof the repeating mechanism by any one of the street-magnets while underthe control of any other of the street-magnets, and means actuated bythe operation of the repeating mechanism for closing thenon-interference circuit, substantially as and for the purposes setforth.

2. In a non-interference repeater for firealarm circuits, thecombination with repeating mechanism, of a plurality of switchescontrolling the same, a corresponding number of street-magnets foractuating said switches, a normally open circuit embracingnon-interference magnets corresponding with the streetmagnets, meanscontrolled by the non-interference magnets for disabling the switchesexcept that of the street-magnet first receiving a signal, and meansactuated by the operation of the repeating mechanism for closing thenon-interference circuit, substantially as and for the purposes setforth.

3. In a non-interference repeater for firealarm circuits, thecombination with repeating mechanism, of a plurality of street-magnets,operating-switches for controlling said mechanism, a normally opencircuit embracing noninterference magnets corresponding with thestreet-magnets, means controlled by each of the street-magnets foroperating the non-interference magnets to disable the switches exceptthat of the street-magnet first receiving a signal and prevent any otherstreet-magnet from controlling the repeating mechanism, and meansactuated by the operation of the repeating mechanism for closing thenon-interference circuit, substantially as and for the purposes setforth.

4. In a non-interference repeater for fire alarm circuits, thecombination with repeating mechanism, of a plurality of street-magnets,a switch operated by each street-magnet controlling the repeatingmechanism, a plurality ofnon-interference magnets, and armature leversfor the non-interference magnets cooperating with said switches, thesaid armature-levers having slots therein, substantially asand for thepurposes set forth.

5. In a non-interference repeater for firealarm circuits, thecombination with repeating mechanism, of a plurality of switchescontrolling the same, corresponding street-magnets actuated by saidswitches, a normally open circuit embracing non-interference magnetscorresponding with the street-magnets, means controlled by thenon-interference magnets for disabling the switches of all thestreetmagnets except the first street-magnet to operate, and meanscontrolled by the repeating mechanism for closing the circuit includingthe non-interference magnets, substantially as and for the purposes setforth.

6, In a non-mterference repeater for firealarm circuits, the combinationwlth repeating mechanism, of a plurality of switches controlling thesame, astreet-magnet for each switch, a non interference magnet for eachstreetmagnet, an armature-lever for each non-interference magnet havinga cut-away portion therein cooperating with the respective switchtherefor, and means controlled by the repeating mechanism for permittingthe armature levers of the non-interference magnets to move to aretracted position, substantially as and for the purposes set forth.

7. In a non-interference repeater for firealarm circuits, thecombination with repeating mechanism, of a plurality of switchescontrolling the same, a street-magnet for each switch, a noninterference magnet for each streetmagnet, an armature-lever for eachnon-interference magnet having a cut-away portion therein cooperatingwith the respective switch therefor, means controlled by the repeatingmechanism for permitting the armature-levers Mass"? of thenon-interference magnets to move to a retracted position, and meansoperated by the repeating mechanism for closing the non-interferencecircuit, substantially as and for the purposes set forth.

8. In a non-interference repeater forfirealarm circuits, the combinationwith repeating mechanism, of a plurality of street-magnets controllingthe same, a normally open circuit embracing non-interference magnetscorresponding with the street-magnets, means controlled by the repeatingmechanism and cooperating with the non-interference magnets fordisabling all the street-magnets except that immediately controlling therepeating mechanism, and means actuated by the operation of therepeating mechanism for closing the non-interference circuit,substantially as and for the purposes set forth.

9. In a non-interference repeater for firealarm circuits, thecombination with repeating mechanism, of a street-magnet, a switchcontrolling the repeating mechanism, connections between said switch andthe armature of the street-magnet, a non-interference magnet, and anarmature therefor having a slot therein adapted to engage with saidswitch, substantially as and for the purposes set forth.

10. In a non-interference repeater for firealarm circuits, thecombination with repeating mechanism, of a street-magnet, a switchcontrolling the repeating mechanism, connections between said switch andthe armature of the street-magnet, a non-interference magnet, anarmature therefor having a slot therein adapted to engage with saidswitch, .and means controlled by the repeating mechanism formechanically releasing said armature, substantially as and for thepurposes set forth.

11. In a non-interference repeater for firealarm circuits, thecombination with repeating mechanism, of a street-magnet, a switchcontrolling the repeating mechanism, connections between said switch andthe armature of the street-magnet, a non-interference magnet, anarmature therefor having a slot therein adapted to engage with saidswitch, means controlled by the repeating mechanism for mechanicallyreleasing said armature, and means operated by the switch for closingthe circuit to the non-interference magnet concurrently with theoperation of the repeating mechanism, substantially as and for thepurposes set forth.

12. In a non-interference repeater for firealarm circuits, thecombination with repeating mechanism, of a street-magnet, a switchcontrolling the repeating mechanism, connections between said switch andthe armature of the street-magnet, a non-interference magnet, anarmature therefor having a slot therein adapted to engage with saidswitch, means controlled by the repeating mechanism for mechanicallyreleasing said armature, means operated by the switch for closing thecircuit to with the operation of the repeating mechanism, and asecondary circuit-closing device in the non-interference circuitcontrolled by the repeating mechanism, substantially as and for thepurposes set forth.

13. In a non-interference repeater for firealarm circuits, thecombination with repeating mechanism and a restoring shaft operatedthereby, of a street-magnet, a switch operated by the street-magnet foreffecting theoperation of the repeating mechanism, a non-interferencemagnet, an armature-lever therefor having a slot therein adapted toengage with said switch, and connections between the restoring-shaft andthe armature-lever of the non-interference magnet for mechanicallyreleasing said armature-lever concurrently with the operation of therepeating mechanism, substantially as and for the purposes set forth.

14. In a non-interference repeater for firealarm circuits, thecombination with repeating mechanism and a restoring-shaft operatedthereby, of a street-magnet, a switch operated by the street-magnet foreffecting the operation of the repeating mechanism, a non-interferencemagnet, an armature-lever therefor having a slot therein adapted toengage with said switch, connections between the restoring-shaft and thearmature-lever of the noninterference magnet for mechanically releasingsaid armature-lever concurrently with the operation of the repeatingmechanism, a switch in the non-interference circuit, and connectionsbetween said switch and restoring-shaft for closing the non-interferencecircuit, substantially as and for the purposes set forth.

15. In a non-interference repeater for firealarm circuits, thecombination with repeating mechanism, of a street-magnet, an armaturetherefor, a bell-crank actuated by said armature, a switch operated bythe bell-crank for controlling the repeating mechanism, and anon-interference magnet and armature cooperating with the bell-crank,substantially as and for the purposes set forth.

16. In a non-interference repeater for firealarm circuits, thecombination with repeating mechanism, of a street-magnet controlling thesame, an armature for said street-magnet, a pin on said armature, a hookfor receiving the pin when the armature is partially attracted, andmeans controlled by the repeating mechanism for mechanically engagingsaid pin with said hook, substantially as and for the purposes setforth.

This specification signed and witnessed this 3d day of October, 1902.

WILLIAM H. KIRNAN Witnesses:

CHAS. W. CORNELL, H. T. BENDER.

